The present disclosure relates generally to an arrangement for, and a method of, capturing images of documents.
Imaging readers, each having a solid-state imager or image sensor, analogous to those conventionally used in consumer digital cameras, have been used to electro-optically read symbols, such as one-dimensional bar code symbols, particularly of the Universal Product Code (UPC) type, and two-dimensional bar code symbols, such as PDF417 and QR codes, and/or non-symbols or documents, such as prescriptions, labels, receipts, driver's licenses, employee badges, payment/loyalty cards, etc., each bearing alphanumeric characters, and some bearing pictures, in many different venues, such as at full-service or self-service, point-of-transaction, retail checkout systems operated by checkout clerks or customers, and located at supermarkets, warehouse clubs, department stores, and other kinds of retailers, as well as at many other types of businesses, for many years.
The imaging reader has a one- or two-dimensional array of photocells or light sensors (also known as pixels), and an imaging lens assembly for capturing return light scattered and/or reflected from a symbol/document being imaged through a scan window over a field of view, and for projecting the return light onto the sensor array to initiate capture of an image of the symbol/document over a range of working distances in which the symbol/document can be read. The imaging reader advantageously includes an aiming light assembly for projecting a visible aiming light beam whose cross-section has a pattern, for example, a generally circular spot or cross-hairs for placement at the center of the symbol/document, or a line for placement across the symbol/document, or a set of framing lines to bound the field of view, to assist an operator in visually locating the symbol/document within the field of view prior to image capture. The imager may include a one- or two-dimensional charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) device and associated circuits for producing and processing electrical signals corresponding to a one- or two-dimensional array of pixel data over the field of view. In the case of a symbol associated with a product, these electrical signals are processed and decoded by a programmed microprocessor or controller into decoded data that identifies the product, and enables information, such as the product's price, to be retrieved from a price database. In the case of a document, these electrical signals are processed by the programmed microprocessor or controller into a picture of the document.
In typical use, the operator holds the imaging reader in his/her hand, actuates the aiming light assembly to emit the aiming beam by actuating a trigger once, visually locates a symbol with the aid of the aiming beam, aims the imaging reader at the symbol, and then captures an image of the symbol by actuating the trigger again. As part of the same transaction in which the symbol was read, or as an independent transaction, the operator may wish to capture an image of a document, such as a medical prescription. This is typically performed by placing the document on a countertop, or in a document capture stand or analogous fixture, each operative for supporting the document while an image of the document is being captured.
Yet, the above-described image capture of documents has not proven to be altogether satisfactory in practice. The document needs to be properly placed and aligned on the countertop or in the stand, and the document must be positioned at a particular working distance from the reader, in order to have substantially the entire image captured in full frame and in focus. It is known to require an operator to employ a ruler to set the correct working distance, because documents of different sizes have to be read at different working distances. It is also known to require an operator to adjust the stand by operating complex position controls. However, both of these known setting/adjustment techniques are laborious in practice, especially for an inexperienced operator who may forego practicing such techniques, with the result that an image of the entire document may not be captured, or the image may be blurred, thereby resulting in a loss of information.
Accordingly, there is a need to capture images of documents without requiring the use of rulers or operating any complex position controls in a non-laborious, easy and rapid manner to insure that substantially the entire image of each document is captured in full frame and in focus.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and locations of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The method and arrangement components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.